#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

int main()
{
    int a = 0, n = 0, t = 0;
    scanf("%d", &a);
    if ((a >= 12))
    {
        n = a / 12;
        t = n * 4 + 2;
        printf("%d", t);
    }
    else {
        printf("2");
    }


    return 0;
}